package main

import "fmt"

func myTest(Myslice []string) string {

	start := Myslice[0]
	for index, value := range start {
		//fmt.Println(index, value)
		for _, value2 := range Myslice {
			if index == len(value2) || value2[index] != byte(value) {
				return start[:index]
			}
		}
	}
	return start
}

func main() {
	Myslice := []string{"java", "qt", "python", "hadoop"}
	//Myslice := []string{"hel", "helIn", "heOnq"}
	data := myTest(Myslice)
	fmt.Println(len(data))
}
